On injection of a substance directly into a patient or via an infusion aggregate one cannot avoid contamination of the air through formation of aerosols or drops. This happens partly during drawing in the medium from the ampoule, in which it is normally contained, to the injection syringe, and partly in connection with the injection itself into the patient or the infusion bottle. This air contamination leads to problems among other things in the form of allergic reactions in the exposed personnel, especially when it is a question of cytotoxic drugs, anaesthetics, media containing isotopes and allergy inducing substances of various kinds.
The same problem with air contamination occurs during handling of poisonous chemicals, for example solvents of different types, in industries, in laboratories, etc.
There are previously known devices for transferring a medicine in liquid form from an ampoule to a bottle without contamination. Such an apparatus is shown for example in the Norwegian Pat. No. 141,537 and it contains a double needle, one end of which is protected by an elastic hood, which the needle can penetrate by pressing together the hood, whereby the needle can be inserted into an ampoule. The opposite end of the needle is pushed through the membrane to a bottle with an infusion solution. This device presupposes that the medicine is already in the ampoule as a solution and therefore need not be dissolved first. Further there is no possibility of using the apparatus without contamination risk to inject the medicine directly into the patient.